docs: def get_amqp_message_by_unit(self, sentry_unit, queue="test",
                                   username="testuser1",
                                   password="changeme",
                                   ssl=False, port=None):
          """Get an amqp message from a rmq juju unit.
  
          :param sentry_unit: sentry unit pointer
          :param queue: message queue, default to test
          :param username: amqp user name, default to testuser1
          :param password: amqp user password
          :param ssl: boolean, default to False
          :param port: amqp port, use defaults if None
          :returns: amqp message body as string.  Raise if get fails.
          """
          connection = self.connect_amqp_by_unit(sentry_unit, ssl=ssl,
                                                 port=port,
                                                 username=username,
                                                 password=password)
          channel = connection.channel()
          method_frame, _, body = channel.basic_get(queue)
  
          if method_frame:
              self.log.debug('Retreived message from {} queue:\n{}'.format(queue,
                                                                           body))
              channel.basic_ack(method_frame.delivery_tag)
              channel.close()
              connection.close()
              return body
          else:
              msg = 'No message retrieved.'
              amulet.raise_status(amulet.FAIL, msg)